Re: Editing of area codes

Hi Jeff -

>Or drill down to:  http://www.nanpa.com/area_codes/index.html
>     MORE ABOUT AREA CODES
>NANPA uses guidelines prepared by the ATIS-sponsored Industry Numbering
>Committee to administer area codes. These guidelines, titled "NPA Allocation
>Plan and Assignment Guidelines," include an application form for requesting
>the assignment of an NPA code. The latest version of the guidelines may be
>found on the ATIS web site at http://www.atis.org/atis/clc/inc/incdocs.htm.

It's been a while since I've been to the NANPA site so I went and looked
around some, including going through to the ATIS site.

Of extreme interest there, U.S. phone numbers will eventually be expanded
to TWELVE digits, with one extra digit added to the end of the area code
and the other extra digit added to the beginning of the exchange, giving
phone numbers in the format

NXX(X)-(X)NXX-XXXX

where the new digits are in parenthesis,
N is any digit 2-9
X is any digit 0-9

Note that area codes will continue to start with 2-9, so going back to the
question that started the thread ... you should NOT allow area codes to
start with 1.  This restriction is extremely unlikely to change at any
point in our lifetimes.

There is planned to be a lead time of ten years, so there is no need to
scramble to increase your telephone number fields, however if you are
creating new files with a phone number field, you may want to make it 12
digits in the file but 10 digits on screens and reports, leaving room there
for the extra digits.

Since international regulations limit the entire length of a phone number,
including the country code, to 15 digits, and since the country code can be
from one to three digits; even though the U.S. country code is only one
digit long, the plan is still to limit the length of phone numbers to 12
digits, leaving room for a full three digit country code.

If you need international phone numbers, you should use a 15 digit phone
number field.  If you store the country code separately, you would have a
three digit country code field and a 14 digit telephone number, editing to
make sure that the combined length does not exceed 15 digits.

Ken
Opinions expressed are my own and do not necessarily represent the views of
my employer or anyone in their right mind.